Method of applying abrading disks to grinding or polishing machines



Aug. 23, 1938. v. e. SCHWENKE 2,127,703

METHOD OF APPLYING ABRADING DISKS TO GRINDING 0R POLISHING MACHINES Filed NOV. 50, 1936 'lll] III/ I I I! I INVENTOR. 'cior' 6. 567.01% Z'e.

RNEYS.

Patented Aug. 23, 1938 METHOD OF APPLYING ABBADING DISKS TO GRINDING R POLISHING MACHINES Victor e. Sohwenke, pea-bu, Mioh., assignor a, Briggs Manufacturing Company. Detroit, Mich a corporation of Michigan Application November so, 1930, Serial No. 113,320

1 Claim. (01. 51-197) This invention relates to means and a method 01' applying abrasive sheets or disks to a grinding or polishing head.

In accordance with previous practice the sheets or disks of abrasive material were laid over the face of the abrading head or block, folded over and around the periphery or side edges of the head and had their free edges secured to the rear face of the head, or to the periphery thereof, by tacks or the like. Thus when the abrasive sheets became worn, the tacks had to be removed and the old sheets replaced by new ones which also had to be tacked to the head. This method of applying the sheets was a slow and awkward one and often the tacks for securing the sheets would cause rips or tears in the sheets during use of the device. Such tears obviously loosened and weakened the abrasive sheets and rendered them unfit for use after a short period of time.

An object of the invention is to provide a new method or mode of applying a sheet or a plurality of sheets of abrasive material, such as sandpaper or emery cloth to an abrading head in a quick, simple and elficient manner.

The above and other objects and advantages of the present invention will appear from the following description and appended claim when considered in conjunction with the accompanying drawing forming a part of this specification.

In said drawing:

Fig. 1 is an elevational view of the abrasive face of a grinding or polishing sheet or disk embodying the invention.

Fig. 2 is a side elevational view, partly in section,- illustrating one form of loading device embodying my invention, together with a grinding head and several of the abrasive sheets or disks embodying the present invention and showing the relative positions of the parts during one step of the mode or method of applying the abrasive sheets to the abrading head; and

Fig. 3 is a view similar to Fig. 2 illustrating the final step of the method or mode of applying and securing abrasive sheets to the abrading head and showing the relative positions of the parts prior to the removal of the loading device from the abrading head.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phrascology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention claimed herein beyond the requirements of the prior art.

Referring now to the drawing, the abrasive element per se embodying the present invention comprises, preferably. a disk-like layer or sheet of sandpaper, emery cloth or other backing material carrying a layer of finely divided abrasive particles or grains. It will be seen that the flexible disk 25 has a materially greater diameter than the circular supporting face iii of the head A, the disk having sufficient area to cover the face of the head and to be wrapped or folded around the peripheral edge of the head so as to completely lap the retaining groove H. The peripherai edge of the disk is provided with a series of deep radially extending slits. Preferably the edge is notched as shown in Fig. 1 into a zigzag formation to provide a series of spike-like or V-shaped projections 26. The slitted or notched edge of the disk 25, which overlies the groove l1 inthe supporting head or compressible backing member I6, is removably clamped in the groove by means of a coil spring 28. Since the member I6 is preferably soft and compressible the flexible disk may be drawn smoothly over the crowned face of the member IB and the marginal edge thereof, and the outlying edge of the disk will be drawn or pulled tightly into the groove by the coil spring. The radial slits or notches in the disk will enable the edge of the disk to accommodate the larger circumference without buckling or causing any material wrinkling of the disk within the groove, and the spike-like projections or prongs 26 permit ready removal of the disk. A number of disks, such as three shown herein by wayof example, may be superimposed and clamped at one time on the support. A worn disk can be readily stripped oiT, without disturbing those beneath or requiring removal of the clamping spring, simply by spreading the spring at any point, prying out and freeing one of the prongs or tabs 26 from beneath the spring, releasing the spring and then grasping the freed tab and stripping the top disk from the support.

Referring now particularly to Figs. 2 and 3, there is shown a loader embodying the present invention for loading or assembling disks upon the polishing head. In practice, and in accordance with my invention, it is customary to apply to the supporting block or abrading head A a plurality of superimposed disk-like sheets of abrading material so that when the topmost sheet has become worn it can be removed to expose the next sheet, thus eliminating the necessity of removing and replacing a single sheet at a time.

The loader of the present invention is shown as a whole at B and comprises, preferably, a circularblock of wood or other suitable material having formed in one portion of its periphery an annular depression or groove II and having attached adiacent the lower edge of its peripheral face, a metal band I! which is held in place upon the block in any suitable manner, as by means of tacks II. This metal band has a flange portion "a, which extends below or beyond the bottom face I4 of the block B. Positioned centrally of the block 80 and in its inner or under face, is a screw threaded stud "having the exposed portion of its shank I8 projecting below or beyond the bottom face 34. The diameter of the block may be substantially the same as the corresponding diameter of the abrading head A but as will be seen in Fig. 3, when the block is placed upon the top face of said abrading head, the projecting portion or flange 32a. of the metal band overlaps a portion of the periphery of said head.

As shown in Fig. 2, the head A has been disconnected from its supporting handle and flexible power shaft (not shown) and inverted upon a flat surface E. A number of abrasive disks 25 is placed or stacked upon the top face of the abrading head A. The loader B is pressed down upon the head A forcing the flange 32a over the edge thereof thus folding the edges of the disks over the edge of the member I0, and drawing the superimposed disks taut across the face of the support. During this movement the shank 36 of the locating pin 35 punctures a hole through the centers of the several abrading disks 2B and forces the surrounding portions of the holes into the aperture I! so that when the head is in use, water fed through the tube 23 can pass through the punctured openings in the disks and impinge upon the surface of the work. As shown in Fig. 3, the disk retaining spring 28, previously referred to, is located in expanded condition within the peripheral groove 3| formed in the block B. After the block has been forced down upon the abrading head (Fig. 3) the spring is rolled or slid downwardly from its position within the groove II and over the outer face of the circular flange Ila. When the spring has been moved beyond the lower edge of the flange and is free of the same, it will contract and spring into the groove or recess ll clamping the notched edges of the disks therein. Since the spring is still under tension it will bind the edge portions ll of the disks firmly in place in the groove H and hold said disks tightly in place upon the head A. The loader B may now be removed and the abrading head A threaded upon the coupling 22 of the flexible hollow shaft 2| until it engages the handle III. The device is now in readiness for use.

After the disks 2! on the head have been used up and it is desired to replace them with new ones, the loader may be mounted in the manner shown in Fig. 3 and the spring 2! rolled back upon the loader until lodged in the groove ll thereby releasing the last of the disks remaining upon the head A. A new supply of disks may then be applied in the manner described above. Thus the replacement of the disks can be accomplished quickly and easily without the use of tacks, screws or special tools.

By virtue of the present invention it is possible to apply one or a plurality of abrading disks or sheets to an abrading head without necessitating the use of tacks, screws or the like for attaching the disks, and to remove or replace the worn disks or sheets with ease and facility.

I claim:

The method of applying an abrading disk or disks to an abrading head having a groove formed in its periphery, which comprises the steps of placing the disk or disks over the working face of the head, forcing an annular ring member down over the head to fold the edges of the disk down over said annular groove, simultaneously puncturing the center of said sheet, and thereafter shifting a ring-like binder device over the fact of said annular ring member and said head to anchor the same in position within the groove and bind the sheet to the head.

VICTOR G. SCHW'ENKE.

cam-Indira or commoner.

Patent 2,127,705.

VICTOR G.

August 23, 1938.

scmmsn.

It is hereby certified that error appears in theprinted specitieation of the above numbered patent requiring correetionas follows: Page 2, second column, line 1 1;, intho claim; for "fast" read face; and that the said Lettors Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office,

Signed and sealed this 1st day of novsmbarfi. n. 19 3.

(Seal) Henry Van Aredale Acting commissioner; of Patents.

has become worn it can be removed to expose the next sheet, thus eliminating the necessity of removing and replacing a single sheet at a time.

The loader of the present invention is shown as a whole at B and comprises, preferably, a circularblock of wood or other suitable material having formed in one portion of its periphery an annular depression or groove II and having attached adiacent the lower edge of its peripheral face, a metal band I! which is held in place upon the block in any suitable manner, as by means of tacks II. This metal band has a flange portion "a, which extends below or beyond the bottom face I4 of the block B. Positioned centrally of the block 80 and in its inner or under face, is a screw threaded stud "having the exposed portion of its shank I8 projecting below or beyond the bottom face 34. The diameter of the block may be substantially the same as the corresponding diameter of the abrading head A but as will be seen in Fig. 3, when the block is placed upon the top face of said abrading head, the projecting portion or flange 32a. of the metal band overlaps a portion of the periphery of said head.

As shown in Fig. 2, the head A has been disconnected from its supporting handle and flexible power shaft (not shown) and inverted upon a flat surface E. A number of abrasive disks 25 is placed or stacked upon the top face of the abrading head A. The loader B is pressed down upon the head A forcing the flange 32a over the edge thereof thus folding the edges of the disks over the edge of the member I0, and drawing the superimposed disks taut across the face of the support. During this movement the shank 36 of the locating pin 35 punctures a hole through the centers of the several abrading disks 2B and forces the surrounding portions of the holes into the aperture I! so that when the head is in use, water fed through the tube 23 can pass through the punctured openings in the disks and impinge upon the surface of the work. As shown in Fig. 3, the disk retaining spring 28, previously referred to, is located in expanded condition within the peripheral groove 3| formed in the block B. After the block has been forced down upon the abrading head (Fig. 3) the spring is rolled or slid downwardly from its position within the groove II and over the outer face of the circular flange Ila. When the spring has been moved beyond the lower edge of the flange and is free of the same, it will contract and spring into the groove or recess ll clamping the notched edges of the disks therein. Since the spring is still under tension it will bind the edge portions ll of the disks firmly in place in the groove H and hold said disks tightly in place upon the head A. The loader B may now be removed and the abrading head A threaded upon the coupling 22 of the flexible hollow shaft 2| until it engages the handle III. The device is now in readiness for use.

After the disks 2! on the head have been used up and it is desired to replace them with new ones, the loader may be mounted in the manner shown in Fig. 3 and the spring 2! rolled back upon the loader until lodged in the groove ll thereby releasing the last of the disks remaining upon the head A. A new supply of disks may then be applied in the manner described above. Thus the replacement of the disks can be accomplished quickly and easily without the use of tacks, screws or special tools.

By virtue of the present invention it is possible to apply one or a plurality of abrading disks or sheets to an abrading head without necessitating the use of tacks, screws or the like for attaching the disks, and to remove or replace the worn disks or sheets with ease and facility.

I claim:

The method of applying an abrading disk or disks to an abrading head having a groove formed in its periphery, which comprises the steps of placing the disk or disks over the working face of the head, forcing an annular ring member down over the head to fold the edges of the disk down over said annular groove, simultaneously puncturing the center of said sheet, and thereafter shifting a ring-like binder device over the fact of said annular ring member and said head to anchor the same in position within the groove and bind the sheet to the head.

VICTOR G. SCHW'ENKE.

cam-Indira or commoner.

Patent 2,127,705.

VICTOR G.

August 23, 1938.

It is hereby certified that error appears in theprinted specitieation of the above numbered patent requiring correetionas follows: Page 2, second column, line 1 1;, intho claim; for "fast" read face; and that the said Lettors Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office,

Signed and sealed this 1st day of novsmbarfi. n. 19 3.

(Seal) Henry Van Aredale Acting commissioner; of Patents. 

